Adding example with small C code to demonstrate progress of memory usage
.\" Copyright (c) 2013, Peter Schiffer (pschiffe@redhat.com)
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.TH MEMUSAGESTAT 1 2013-04-10 "GNU glibc 2.18" "Memory diagnostic tools"
.SH NAME
memusagestat \- generate graphic from memory profiling data
.SH SYNOPSIS
.BR memusagestat " [\fIOPTION\fR]... \fIDATAFILE\fR [\fIOUTFILE\fR]"
.SH DESCRIPTION
.B memusagestat
can create a PNG file with graphical representation of memory profiling
data.
Red line in the graph shows the heap usage (allocated memory),
green line shows the stack usage,
x-scale number of memory handling functions calls or time (\fB-t\fR option).
.I DATAFILE
is a binary data file generated by
.BR memusage (1)
utility with
.B -d
option.
.SH OPTIONS
.TP
.BI \-o\ file \fR,\ \fB\-\-output= file
Name of the output file.
.TP
.BI \-s\ string \fR,\ \fB\-\-string= string
Title string used in the output graphic.
.TP
.BI \-t\fR,\ \fB\-\-time
Generate output linear to time
(default is linear to number of function calls).
.TP
.BI \-T\fR,\ \fB\-\-total
Also draw graph for total memory consumption.
.TP
.BI \-x\ size \fR,\ \fB\-\-x-size= size
Make graphic size pixels wide.
.TP
.BI \-y\ size \fR,\ \fB\-\-y\-size= size
Make graphic size pixels high.
.TP
.BI \-?\fR,\ \fB\-\-help
Print help and exit.
.TP
.BI \fB\-\-usage
Print a short usage message and exit.
.TP
.BI \-V\fR,\ \fB\-\-version
Print version information and exit.
.SH EXAMPLES
Here is a simple program \fImemusagestatexample.c\fR simulating increase
and decrease of memory usage:
.RS 4
#include <stdio.h>
.RS 0
#include <stdlib.h>
.RE
.RS 0
#define CYCLES 20
.RE
int main(int argc, char ** argv) {
int i, j;
int *p = NULL;
printf("malloc: %d\\n", sizeof(int)*100);
p = malloc(sizeof(int)*100);
for (i = 0; i < CYCLES; i++) {
if (i < CYCLES/2) j = i; else j--;
printf("realloc: %d\\n", sizeof(int)*((j)*50 + 110));
p = realloc(p, sizeof(int)*(j*50 + 100));
printf("realloc: %d\\n", sizeof(int)*((j+1)*150 + 110));
p = realloc(p, sizeof(int)*((j+1)*150 + 110));
}
free(p);
return 0;
.RS 0
}
.RE
.RE
After compiling and running the following, you can see progress of
memory usage (memusagestatexample.png):
memusage --data=memusagestatexample.dat ./memusagestatexample
.RS 0
memusagestat memusagestatexample.dat memusagestatexample.png
.RE
.SH BUGS
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
.SH SEE ALSO
.BR memusage (1)